L-H Threshold Studies in NSTX

Kaye, S M ; Battaglia, D ; Bell, R E ; Chang, C S ; Hosea, J ; Kugel, H ; LeBlanc, B P ; Meyer, H ; Park, G Y

关键词: ASPECT RATIO;    CONFINEMENT;    DEUTERIUM;    HELIUM;    LITHIUM;    PLASMA;    SPATIAL RESOLUTION H-Mode Plasma Confinement;    Tokamaks;    NSTX;   

DOI  :  10.2172/1028184
RP-ID  :  PPPL-4635
PID  :  OSTI ID: 1028184
Others  :  TRN: US1106004

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

Recent experiments in the low aspect ratio National Spherical Torus Experiment (NSTX) have been run in support of the high priority ITER and ITPA issue of access to the H-mode. Specifically, a series of experiments showed reduced power threshold values for deuterium vs helium plasmas, and for plasmas with lower current, lower triangularity and with lithium conditioning. Application of n=3 fields at the plasma edge resulted in higher power thresholds. To within the constraints of temporal and spatial resolutions, no systematic difference in T{sub e}, n{sub e}, p{sub e}, T{sub i}, v or their derivatives was found in discharges that transitioned into the H-mode versus those at slightly lower power that did not. Finally, H{sub 98y,2} {approx} 1 confinement quality could be achieved for powers just above the threshold power in ELM-free conditions.